3 Задача

#include <iostream>

using namespace std;
int gcd(int a, int b) {
	if (b == 0)
		return a;

	return gcd(b, a % b);
}

int main() {
	int counter = 1, a, b, temp, k  = 0, kek = 0,sas;
	cin >> a;
	k = a - 1;
	while (k != 0) {
		if (gcd(k, a) == 1) {
			cout << k << endl;
		}
		k--;
	}
	system("pause");
	return 0;
}